/*
 * qrencode - QR Code encoder
 *
 * Input data chunk class
 * Copyright (C) 2006-2011 Kentaro Fukuchi <kentaro@fukuchi.org>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#if HAVE_CONFIG_H
# include "config.h"
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

#include "qrencode.h"
#include "qrspec.h"
#include "mqrspec.h"
#include "bitstream.h"
#include "qrinput.h"

/******************************************************************************
 * Utilities
 *****************************************************************************/
int QRinput_isSplittableMode(QRencodeMode mode)
{
    return (mode >= QR_MODE_NUM && mode <= QR_MODE_KANJI);
}

/******************************************************************************
 * Entry of input data
 *****************************************************************************/

static QRinput_List *QRinput_List_newEntry(QRencodeMode mode, int size, const unsigned char *data)
{
    QRinput_List *entry;

    if(QRinput_check(mode, size, data)) {
        errno = EINVAL;
        return NULL;
    }

    entry = (QRinput_List *)malloc(sizeof(QRinput_List));
    if(entry == NULL) return NULL;

    entry->mode = mode;
    entry->size = size;
    if(size > 0) {
        entry->data = (unsigned char *)malloc(size);
        if(entry->data == NULL) {
            free(entry);
            return NULL;
        }
        memcpy(entry->data, data, size);
    }
    entry->bstream = NULL;
    entry->next = NULL;

    return entry;
}

static void QRinput_List_freeEntry(QRinput_List *entry)
{
    if(entry != NULL) {
        free(entry->data);
        BitStream_free(entry->bstream);
        free(entry);
    }
}

static QRinput_List *QRinput_List_dup(QRinput_List *entry)
{
    QRinput_List *n;

    n = (QRinput_List *)malloc(sizeof(QRinput_List));
    if(n == NULL) return NULL;

    n->mode = entry->mode;
    n->size = entry->size;
    n->data = (unsigned char *)malloc(n->size);
    if(n->data == NULL) {
        free(n);
        return NULL;
    }
    memcpy(n->data, entry->data, entry->size);
    n->bstream = NULL;
    n->next = NULL;

    return n;
}

/******************************************************************************
 * Input Data
 *****************************************************************************/

QRinput *QRinput_new(void)
{
    return QRinput_new2(0, QR_ECLEVEL_L);
}

QRinput *QRinput_new2(int version, QRecLevel level)
{
    QRinput *input;

    if(version < 0 || version > QRSPEC_VERSION_MAX || level > QR_ECLEVEL_H) {
        errno = EINVAL;
        return NULL;
    }

    input = (QRinput *)malloc(sizeof(QRinput));
    if(input == NULL) return NULL;

    input->head = NULL;
    input->tail = NULL;
    input->version = version;
    input->level = level;
    input->mqr = 0;
    input->fnc1 = 0;

    return input;
}

QRinput *QRinput_newMQR(int version, QRecLevel level)
{
    QRinput *input;

    if(version <= 0 || version > MQRSPEC_VERSION_MAX) goto INVALID;
    if((MQRspec_getECCLength(version, level) == 0)) goto INVALID;

    input = QRinput_new2(version, level);
    if(input == NULL) return NULL;

    input->mqr = 1;

    return input;

INVALID:
    errno = EINVAL;
    return NULL;
}

int QRinput_getVersion(QRinput *input)
{
    return input->version;
}

int QRinput_setVersion(QRinput *input, int version)
{
    if(input->mqr || version < 0 || version > QRSPEC_VERSION_MAX) {
        errno = EINVAL;
        return -1;
    }

    input->version = version;

    return 0;
}

QRecLevel QRinput_getErrorCorrectionLevel(QRinput *input)
{
    return input->level;
}

int QRinput_setErrorCorrectionLevel(QRinput *input, QRecLevel level)
{
    if(input->mqr || level > QR_ECLEVEL_H) {
        errno = EINVAL;
        return -1;
    }

    input->level = level;

    return 0;
}

int QRinput_setVersionAndErrorCorrectionLevel(QRinput *input, int version, QRecLevel level)
{
    if(input->mqr) {
        if(version <= 0 || version > MQRSPEC_VERSION_MAX) goto INVALID;
        if((MQRspec_getECCLength(version, level) == 0)) goto INVALID;
    } else {
        if(version < 0 || version > QRSPEC_VERSION_MAX) goto INVALID;
        if(level > QR_ECLEVEL_H) goto INVALID;
    }

    input->version = version;
    input->level = level;

    return 0;

INVALID:
    errno = EINVAL;
    return -1;
}

static void QRinput_appendEntry(QRinput *input, QRinput_List *entry)
{
    if(input->tail == NULL) {
        input->head = entry;
        input->tail = entry;
    } else {
        input->tail->next = entry;
        input->tail = entry;
    }
    entry->next = NULL;
}

int QRinput_append(QRinput *input, QRencodeMode mode, int size, const unsigned char *data)
{
    QRinput_List *entry;

    entry = QRinput_List_newEntry(mode, size, data);
    if(entry == NULL) {
        return -1;
    }

    QRinput_appendEntry(input, entry);

    return 0;
}

/**
 * Insert a structured-append header to the head of the input data.
 * @param input input data.
 * @param size number of structured symbols.
 * @param index index number of the symbol. (1 <= index <= size)
 * @param parity parity among input data. (NOTE: each symbol of a set of structured symbols has the same parity data)
 * @retval 0 success.
 * @retval -1 error occurred and errno is set to indeicate the error. See Execptions for the details.
 * @throw EINVAL invalid parameter.
 * @throw ENOMEM unable to allocate memory.
 */
static int QRinput_insertStructuredAppendHeader(QRinput *input, int size, int index, unsigned char parity)
{
    QRinput_List *entry;
    unsigned char buf[3];

    if(size > MAX_STRUCTURED_SYMBOLS) {
        errno = EINVAL;
        return -1;
    }
    if(index <= 0 || index > MAX_STRUCTURED_SYMBOLS) {
        errno = EINVAL;
        return -1;
    }

    buf[0] = (unsigned char)size;
    buf[1] = (unsigned char)index;
    buf[2] = parity;
    entry = QRinput_List_newEntry(QR_MODE_STRUCTURE, 3, buf);
    if(entry == NULL) {
        return -1;
    }

    entry->next = input->head;
    input->head = entry;

    return 0;
}

int QRinput_appendECIheader(QRinput *input, unsigned int ecinum)
{
    unsigned char data[4];

    if(ecinum > 999999) {
        errno = EINVAL;
        return -1;
    }

    /* We manually create byte array of ecinum because
     (unsigned char *)&ecinum may cause bus error on some architectures, */
    data[0] = ecinum & 0xff;
    data[1] = (ecinum >>  8) & 0xff;
    data[2] = (ecinum >> 16) & 0xff;
    data[3] = (ecinum >> 24) & 0xff;
    return QRinput_append(input, QR_MODE_ECI, 4, data);
}

void QRinput_free(QRinput *input)
{
    QRinput_List *list, *next;

    if(input != NULL) {
        list = input->head;
        while(list != NULL) {
            next = list->next;
            QRinput_List_freeEntry(list);
            list = next;
        }
        free(input);
    }
}

static unsigned char QRinput_calcParity(QRinput *input)
{
    unsigned char parity = 0;
    QRinput_List *list;
    int i;

    list = input->head;
    while(list != NULL) {
        if(list->mode != QR_MODE_STRUCTURE) {
            for(i=list->size-1; i>=0; i--) {
                parity ^= list->data[i];
            }
        }
        list = list->next;
    }

    return parity;
}

QRinput *QRinput_dup(QRinput *input)
{
    QRinput *n;
    QRinput_List *list, *e;

    if(input->mqr) {
        n = QRinput_newMQR(input->version, input->level);
    } else {
        n = QRinput_new2(input->version, input->level);
    }
    if(n == NULL) return NULL;

    list = input->head;
    while(list != NULL) {
        e = QRinput_List_dup(list);
        if(e == NULL) {
            QRinput_free(n);
            return NULL;
        }
        QRinput_appendEntry(n, e);
        list = list->next;
    }

    return n;
}

/******************************************************************************
 * Numeric data
 *****************************************************************************/

/**
 * Check the input data.
 * @param size
 * @param data
 * @return result
 */
static int QRinput_checkModeNum(int size, const char *data)
{
    int i;

    for(i=0; i<size; i++) {
        if(data[i] < '0' || data[i] > '9')
            return -1;
    }

    return 0;
}

/**
 * Estimates the length of the encoded bit stream of numeric data.
 * @param size
 * @return number of bits
 */
int QRinput_estimateBitsModeNum(int size)
{
    int w;
    int bits;

    w = size / 3;
    bits = w * 10;
    switch(size - w * 3) {
    case 1:
        bits += 4;
        break;
    case 2:
        bits += 7;
        break;
    default:
        break;
    }

    return bits;
}

/**
 * Convert the number data to a bit stream.
 * @param entry
 * @param mqr
 * @retval 0 success
 * @retval -1 an error occurred and errno is set to indeicate the error.
 *            See Execptions for the details.
 * @throw ENOMEM unable to allocate memory.
 */
static int QRinput_encodeModeNum(QRinput_List *entry, int version, int mqr)
{
    int words, i, ret;
    unsigned int val;

    entry->bstream = BitStream_new();
    if(entry->bstream == NULL) return -1;

    if(mqr) {
        if(version > 1) {
            ret = BitStream_appendNum(entry->bstream, version - 1, MQRSPEC_MODEID_NUM);
            if(ret < 0) goto ABORT;
        }
        ret = BitStream_appendNum(entry->bstream, MQRspec_lengthIndicator(QR_MODE_NUM, version), entry->size);
        if(ret < 0) goto ABORT;
    } else {
        ret = BitStream_appendNum(entry->bstream, 4, QRSPEC_MODEID_NUM);
        if(ret < 0) goto ABORT;

        ret = BitStream_appendNum(entry->bstream, QRspec_lengthIndicator(QR_MODE_NUM, version), entry->size);
        if(ret < 0) goto ABORT;
    }

    words = entry->size / 3;
    for(i=0; i<words; i++) {
        val  = (entry->data[i*3  ] - '0') * 100;
        val += (entry->data[i*3+1] - '0') * 10;
        val += (entry->data[i*3+2] - '0');

        ret = BitStream_appendNum(entry->bstream, 10, val);
        if(ret < 0) goto ABORT;
    }

    if(entry->size - words * 3 == 1) {
        val = entry->data[words*3] - '0';
        ret = BitStream_appendNum(entry->bstream, 4, val);
        if(ret < 0) goto ABORT;
    } else if(entry->size - words * 3 == 2) {
        val  = (entry->data[words*3  ] - '0') * 10;
        val += (entry->data[words*3+1] - '0');
        BitStream_appendNum(entry->bstream, 7, val);
        if(ret < 0) goto ABORT;
    }

    return 0;
ABORT:
    BitStream_free(entry->bstream);
    entry->bstream = NULL;
    return -1;
}

/******************************************************************************
 * Alphabet-numeric data
 *****************************************************************************/

const signed char QRinput_anTable[128] = {
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    36, -1, -1, -1, 37, 38, -1, -1, -1, -1, 39, 40, -1, 41, 42, 43,
    0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 44, -1, -1, -1, -1, -1,
    -1, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24,
    25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
};

/**
 * Check the input data.
 * @param size
 * @param data
 * @return result
 */
static int QRinput_checkModeAn(int size, const char *data)
{
    int i;

    for(i=0; i<size; i++) {
        if(QRinput_lookAnTable(data[i]) < 0)
            return -1;
    }

    return 0;
}

/**
 * Estimates the length of the encoded bit stream of alphabet-numeric data.
 * @param size
 * @return number of bits
 */
int QRinput_estimateBitsModeAn(int size)
{
    int w;
    int bits;

    w = size / 2;
    bits = w * 11;
    if(size & 1) {
        bits += 6;
    }

    return bits;
}

/**
 * Convert the alphabet-numeric data to a bit stream.
 * @param entry
 * @param mqr
 * @retval 0 success
 * @retval -1 an error occurred and errno is set to indeicate the error.
 *            See Execptions for the details.
 * @throw ENOMEM unable to allocate memory.
 * @throw EINVAL invalid version.
 */
static int QRinput_encodeModeAn(QRinput_List *entry, int version, int mqr)
{
    int words, i, ret;
    unsigned int val;

    entry->bstream = BitStream_new();
    if(entry->bstream == NULL) return -1;

    if(mqr) {
        if(version < 2) {
            errno = EINVAL;
            goto ABORT;
        }
        ret = BitStream_appendNum(entry->bstream, version - 1, MQRSPEC_MODEID_AN);
        if(ret < 0) goto ABORT;
        ret = BitStream_appendNum(entry->bstream, MQRspec_lengthIndicator(QR_MODE_AN, version), entry->size);
        if(ret < 0) goto ABORT;
    } else {
        ret = BitStream_appendNum(entry->bstream, 4, QRSPEC_MODEID_AN);
        if(ret < 0) goto ABORT;
        ret = BitStream_appendNum(entry->bstream, QRspec_lengthIndicator(QR_MODE_AN, version), entry->size);
        if(ret < 0) goto ABORT;
    }

    words = entry->size / 2;
    for(i=0; i<words; i++) {
        val  = (unsigned int)QRinput_lookAnTable(entry->data[i*2  ]) * 45;
        val += (unsigned int)QRinput_lookAnTable(entry->data[i*2+1]);

        ret = BitStream_appendNum(entry->bstream, 11, val);
        if(ret < 0) goto ABORT;
    }

    if(entry->size & 1) {
        val = (unsigned int)QRinput_lookAnTable(entry->data[words * 2]);

        ret = BitStream_appendNum(entry->bstream, 6, val);
        if(ret < 0) goto ABORT;
    }

    return 0;
ABORT:
    BitStream_free(entry->bstream);
    entry->bstream = NULL;
    return -1;
}

/******************************************************************************
 * 8 bit data
 *****************************************************************************/

/**
 * Estimates the length of the encoded bit stream of 8 bit data.
 * @param size
 * @return number of bits
 */
int QRinput_estimateBitsMode8(int size)
{
    return size * 8;
}

/**
 * Convert the 8bits data to a bit stream.
 * @param entry
 * @param mqr
 * @retval 0 success
 * @retval -1 an error occurred and errno is set to indeicate the error.
 *            See Execptions for the details.
 * @throw ENOMEM unable to allocate memory.
 */
static int QRinput_encodeMode8(QRinput_List *entry, int version, int mqr)
{
    int ret;

    entry->bstream = BitStream_new();
    if(entry->bstream == NULL) return -1;

    if(mqr) {
        if(version < 3) {
            errno = EINVAL;
            goto ABORT;
        }
        ret = BitStream_appendNum(entry->bstream, version - 1, MQRSPEC_MODEID_8);
        if(ret < 0) goto ABORT;
        ret = BitStream_appendNum(entry->bstream, MQRspec_lengthIndicator(QR_MODE_8, version), entry->size);
        if(ret < 0) goto ABORT;
    } else {
        ret = BitStream_appendNum(entry->bstream, 4, QRSPEC_MODEID_8);
        if(ret < 0) goto ABORT;
        ret = BitStream_appendNum(entry->bstream, QRspec_lengthIndicator(QR_MODE_8, version), entry->size);
        if(ret < 0) goto ABORT;
    }

    ret = BitStream_appendBytes(entry->bstream, entry->size, entry->data);
    if(ret < 0) goto ABORT;

    return 0;
ABORT:
    BitStream_free(entry->bstream);
    entry->bstream = NULL;
    return -1;
}


/******************************************************************************
 * Kanji data
 *****************************************************************************/

/**
 * Estimates the length of the encoded bit stream of kanji data.
 * @param size
 * @return number of bits
 */
int QRinput_estimateBitsModeKanji(int size)
{
    return (size / 2) * 13;
}

/**
 * Check the input data.
 * @param size
 * @param data
 * @return result
 */
static int QRinput_checkModeKanji(int size, const unsigned char *data)
{
    int i;
    unsigned int val;

    if(size & 1)
        return -1;

    for(i=0; i<size; i+=2) {
        val = ((unsigned int)data[i] << 8) | data[i+1];
        if(val < 0x8140 || (val > 0x9ffc && val < 0xe040) || val > 0xebbf) {
            return -1;
        }
    }

    return 0;
}

/**
 * Convert the kanji data to a bit stream.
 * @param entry
 * @param mqr
 * @retval 0 success
 * @retval -1 an error occurred and errno is set to indeicate the error.
 *            See Execptions for the details.
 * @throw ENOMEM unable to allocate memory.
 * @throw EINVAL invalid version.
 */
static int QRinput_encodeModeKanji(QRinput_List *entry, int version, int mqr)
{
    int ret, i;
    unsigned int val, h;

    entry->bstream = BitStream_new();
    if(entry->bstream == NULL) return -1;

    if(mqr) {
        if(version < 2) {
            errno = EINVAL;
            goto ABORT;
        }
        ret = BitStream_appendNum(entry->bstream, version - 1, MQRSPEC_MODEID_KANJI);
        if(ret < 0) goto ABORT;
        ret = BitStream_appendNum(entry->bstream, MQRspec_lengthIndicator(QR_MODE_KANJI, version), entry->size/2);
        if(ret < 0) goto ABORT;
    } else {
        ret = BitStream_appendNum(entry->bstream, 4, QRSPEC_MODEID_KANJI);
        if(ret < 0) goto ABORT;
        ret = BitStream_appendNum(entry->bstream, QRspec_lengthIndicator(QR_MODE_KANJI, version), entry->size/2);
        if(ret < 0) goto ABORT;
    }

    for(i=0; i<entry->size; i+=2) {
        val = ((unsigned int)entry->data[i] << 8) | entry->data[i+1];
        if(val <= 0x9ffc) {
            val -= 0x8140;
        } else {
            val -= 0xc140;
        }
        h = (val >> 8) * 0xc0;
        val = (val & 0xff) + h;

        ret = BitStream_appendNum(entry->bstream, 13, val);
        if(ret < 0) goto ABORT;
    }

    return 0;
ABORT:
    BitStream_free(entry->bstream);
    entry->bstream = NULL;
    return -1;
}

/******************************************************************************
 * Structured Symbol
 *****************************************************************************/

/**
 * Convert a structure symbol code to a bit stream.
 * @param entry
 * @param mqr
 * @retval 0 success
 * @retval -1 an error occurred and errno is set to indeicate the error.
 *            See Execptions for the details.
 * @throw ENOMEM unable to allocate memory.
 * @throw EINVAL invalid entry.
 */
static int QRinput_encodeModeStructure(QRinput_List *entry, int mqr)
{
    int ret;

    if(mqr) {
        errno = EINVAL;
        return -1;
    }
    entry->bstream = BitStream_new();
    if(entry->bstream == NULL) return -1;

    ret = BitStream_appendNum(entry->bstream, 4, QRSPEC_MODEID_STRUCTURE);
    if(ret < 0) goto ABORT;
    ret = BitStream_appendNum(entry->bstream, 4, entry->data[1] - 1);
    if(ret < 0) goto ABORT;
    ret = BitStream_appendNum(entry->bstream, 4, entry->data[0] - 1);
    if(ret < 0) goto ABORT;
    ret = BitStream_appendNum(entry->bstream, 8, entry->data[2]);
    if(ret < 0) goto ABORT;

    return 0;
ABORT:
    BitStream_free(entry->bstream);
    entry->bstream = NULL;
    return -1;
}

/******************************************************************************
 * FNC1
 *****************************************************************************/

static int QRinput_checkModeFNC1Second(int size, const unsigned char *data)
{
    if(size != 1) return -1;

    return 0;
}

static int QRinput_encodeModeFNC1Second(QRinput_List *entry, int version)
{
    int ret;

    entry->bstream = BitStream_new();
    if(entry->bstream == NULL) return -1;

    ret = BitStream_appendNum(entry->bstream, 4, QRSPEC_MODEID_FNC1SECOND);
    if(ret < 0) goto ABORT;

    ret = BitStream_appendBytes(entry->bstream, 1, entry->data);
    if(ret < 0) goto ABORT;

    return 0;
ABORT:
    BitStream_free(entry->bstream);
    entry->bstream = NULL;
    return -1;
}

/******************************************************************************
 * ECI header
 *****************************************************************************/
static unsigned int QRinput_decodeECIfromByteArray(unsigned char *data)
{
    int i;
    unsigned int ecinum;

    ecinum = 0;
    for(i=0; i<4; i++) {
        ecinum = ecinum << 8;
        ecinum |= data[3-i];
    }

    return ecinum;
}

int QRinput_estimateBitsModeECI(unsigned char *data)
{
    unsigned int ecinum;

    ecinum = QRinput_decodeECIfromByteArray(data);;

    /* See Table 4 of JISX 0510:2004 pp.17. */
    if(ecinum < 128) {
        return MODE_INDICATOR_SIZE + 8;
    } else if(ecinum < 16384) {
        return MODE_INDICATOR_SIZE + 16;
    } else {
        return MODE_INDICATOR_SIZE + 24;
    }
}

static int QRinput_encodeModeECI(QRinput_List *entry, int version)
{
    int ret, words;
    unsigned int ecinum, code;

    entry->bstream = BitStream_new();
    if(entry->bstream == NULL) return -1;

    ecinum = QRinput_decodeECIfromByteArray(entry->data);;

    /* See Table 4 of JISX 0510:2004 pp.17. */
    if(ecinum < 128) {
        words = 1;
        code = ecinum;
    } else if(ecinum < 16384) {
        words = 2;
        code = 0x8000 + ecinum;
    } else {
        words = 3;
        code = 0xc0000 + ecinum;
    }

    ret = BitStream_appendNum(entry->bstream, 4, QRSPEC_MODEID_ECI);
    if(ret < 0) goto ABORT;

    ret = BitStream_appendNum(entry->bstream, words * 8, code);
    if(ret < 0) goto ABORT;

    return 0;
ABORT:
    BitStream_free(entry->bstream);
    entry->bstream = NULL;
    return -1;
}

/******************************************************************************
 * Validation
 *****************************************************************************/

int QRinput_check(QRencodeMode mode, int size, const unsigned char *data)
{
    if((mode == QR_MODE_FNC1FIRST && size < 0) || size <= 0) return -1;

    switch(mode) {
    case QR_MODE_NUM:
        return QRinput_checkModeNum(size, (const char *)data);
    case QR_MODE_AN:
        return QRinput_checkModeAn(size, (const char *)data);
    case QR_MODE_KANJI:
        return QRinput_checkModeKanji(size, data);
    case QR_MODE_8:
        return 0;
    case QR_MODE_STRUCTURE:
        return 0;
    case QR_MODE_ECI:
        return 0;
    case QR_MODE_FNC1FIRST:
        return 0;
    case QR_MODE_FNC1SECOND:
        return QRinput_checkModeFNC1Second(size, data);
    case QR_MODE_NUL:
        break;
    }

    return -1;
}

/******************************************************************************
 * Estimation of the bit length
 *****************************************************************************/

/**
 * Estimates the length of the encoded bit stream on the current version.
 * @param entry
 * @param version version of the symbol
 * @param mqr
 * @return number of bits
 */
static int QRinput_estimateBitStreamSizeOfEntry(QRinput_List *entry, int version, int mqr)
{
    int bits = 0;
    int l, m;
    int num;

    if(version == 0) version = 1;

    switch(entry->mode) {
    case QR_MODE_NUM:
        bits = QRinput_estimateBitsModeNum(entry->size);
        break;
    case QR_MODE_AN:
        bits = QRinput_estimateBitsModeAn(entry->size);
        break;
    case QR_MODE_8:
        bits = QRinput_estimateBitsMode8(entry->size);
        break;
    case QR_MODE_KANJI:
        bits = QRinput_estimateBitsModeKanji(entry->size);
        break;
    case QR_MODE_STRUCTURE:
        return STRUCTURE_HEADER_SIZE;
    case QR_MODE_ECI:
        bits = QRinput_estimateBitsModeECI(entry->data);
        break;
    case QR_MODE_FNC1FIRST:
        return MODE_INDICATOR_SIZE;
        break;
    case QR_MODE_FNC1SECOND:
        return MODE_INDICATOR_SIZE + 8;
    default:
        return 0;
    }

    if(mqr) {
        l = QRspec_lengthIndicator(entry->mode, version);
        m = version - 1;
        bits += l + m;
    } else {
        l = QRspec_lengthIndicator(entry->mode, version);
        m = 1 << l;
        num = (entry->size + m - 1) / m;

        bits += num * (MODE_INDICATOR_SIZE + l);
    }

    return bits;
}

/**
 * Estimates the length of the encoded bit stream of the data.
 * @param input input data
 * @param version version of the symbol
 * @return number of bits
 */
static int QRinput_estimateBitStreamSize(QRinput *input, int version)
{
    QRinput_List *list;
    int bits = 0;

    list = input->head;
    while(list != NULL) {
        bits += QRinput_estimateBitStreamSizeOfEntry(list, version, input->mqr);
        list = list->next;
    }

    return bits;
}

/**
 * Estimates the required version number of the symbol.
 * @param input input data
 * @return required version number
 */
static int QRinput_estimateVersion(QRinput *input)
{
    int bits;
    int version, prev;

    version = 0;
    do {
        prev = version;
        bits = QRinput_estimateBitStreamSize(input, prev);
        version = QRspec_getMinimumVersion((bits + 7) / 8, input->level);
        if (version < 0) {
            return -1;
        }
    } while (version > prev);

    return version;
}

/**
 * Returns required length in bytes for specified mode, version and bits.
 * @param mode
 * @param version
 * @param bits
 * @return required length of code words in bytes.
 */
static int QRinput_lengthOfCode(QRencodeMode mode, int version, int bits)
{
    int payload, size, chunks, remain, maxsize;

    payload = bits - 4 - QRspec_lengthIndicator(mode, version);
    switch(mode) {
    case QR_MODE_NUM:
        chunks = payload / 10;
        remain = payload - chunks * 10;
        size = chunks * 3;
        if(remain >= 7) {
            size += 2;
        } else if(remain >= 4) {
            size += 1;
        }
        break;
    case QR_MODE_AN:
        chunks = payload / 11;
        remain = payload - chunks * 11;
        size = chunks * 2;
        if(remain >= 6) size++;
        break;
    case QR_MODE_8:
        size = payload / 8;
        break;
    case QR_MODE_KANJI:
        size = (payload / 13) * 2;
        break;
    case QR_MODE_STRUCTURE:
        size = payload / 8;
        break;
    default:
        size = 0;
        break;
    }
    maxsize = QRspec_maximumWords(mode, version);
    if(size < 0) size = 0;
    if(maxsize > 0 && size > maxsize) size = maxsize;

    return size;
}

/******************************************************************************
 * Data conversion
 *****************************************************************************/

/**
 * Convert the input data in the data chunk to a bit stream.
 * @param entry
 * @return number of bits (>0) or -1 for failure.
 */
static int QRinput_encodeBitStream(QRinput_List *entry, int version, int mqr)
{
    int words, ret;
    QRinput_List *st1 = NULL, *st2 = NULL;

    if(entry->bstream != NULL) {
        BitStream_free(entry->bstream);
        entry->bstream = NULL;
    }

    words = QRspec_maximumWords(entry->mode, version);
    if(words != 0 && entry->size > words) {
        st1 = QRinput_List_newEntry(entry->mode, words, entry->data);
        if(st1 == NULL) goto ABORT;
        st2 = QRinput_List_newEntry(entry->mode, entry->size - words, &entry->data[words]);
        if(st2 == NULL) goto ABORT;

        ret = QRinput_encodeBitStream(st1, version, mqr);
        if(ret < 0) goto ABORT;
        ret = QRinput_encodeBitStream(st2, version, mqr);
        if(ret < 0) goto ABORT;
        entry->bstream = BitStream_new();
        if(entry->bstream == NULL) goto ABORT;
        ret = BitStream_append(entry->bstream, st1->bstream);
        if(ret < 0) goto ABORT;
        ret = BitStream_append(entry->bstream, st2->bstream);
        if(ret < 0) goto ABORT;
        QRinput_List_freeEntry(st1);
        QRinput_List_freeEntry(st2);
    } else {
        ret = 0;
        switch(entry->mode) {
        case QR_MODE_NUM:
            ret = QRinput_encodeModeNum(entry, version, mqr);
            break;
        case QR_MODE_AN:
            ret = QRinput_encodeModeAn(entry, version, mqr);
            break;
        case QR_MODE_8:
            ret = QRinput_encodeMode8(entry, version, mqr);
            break;
        case QR_MODE_KANJI:
            ret = QRinput_encodeModeKanji(entry, version, mqr);
            break;
        case QR_MODE_STRUCTURE:
            ret = QRinput_encodeModeStructure(entry, mqr);
            break;
        case QR_MODE_ECI:
            ret = QRinput_encodeModeECI(entry, version);
            break;
        case QR_MODE_FNC1SECOND:
            ret = QRinput_encodeModeFNC1Second(entry, version);
        default:
            break;
        }
        if(ret < 0) return -1;
    }

    return BitStream_size(entry->bstream);
ABORT:
    QRinput_List_freeEntry(st1);
    QRinput_List_freeEntry(st2);
    return -1;
}

/**
 * Convert the input data to a bit stream.
 * @param input input data.
 * @retval 0 success
 * @retval -1 an error occurred and errno is set to indeicate the error.
 *            See Execptions for the details.
 * @throw ENOMEM unable to allocate memory.
 */
static int QRinput_createBitStream(QRinput *input)
{
    QRinput_List *list;
    int bits, total = 0;

    list = input->head;
    while(list != NULL) {
        bits = QRinput_encodeBitStream(list, input->version, input->mqr);
        if(bits < 0) return -1;
        total += bits;
        list = list->next;
    }

    return total;
}

/**
 * Convert the input data to a bit stream.
 * When the version number is given and that is not sufficient, it is increased
 * automatically.
 * @param input input data.
 * @retval 0 success
 * @retval -1 an error occurred and errno is set to indeicate the error.
 *            See Execptions for the details.
 * @throw ENOMEM unable to allocate memory.
 * @throw ERANGE input is too large.
 */
static int QRinput_convertData(QRinput *input)
{
    int bits;
    int ver;

    ver = QRinput_estimateVersion(input);
    if(ver > QRinput_getVersion(input)) {
        QRinput_setVersion(input, ver);
    }

    for(;;) {
        bits = QRinput_createBitStream(input);
        if(bits < 0) return -1;
        ver = QRspec_getMinimumVersion((bits + 7) / 8, input->level);
        if(ver < 0) {
            errno = ERANGE;
            return -1;
        } else if(ver > QRinput_getVersion(input)) {
            QRinput_setVersion(input, ver);
        } else {
            break;
        }
    }

    return 0;
}

/**
 * Append padding bits for the input data.
 * @param bstream Bitstream to be appended.
 * @param input input data.
 * @retval 0 success
 * @retval -1 an error occurred and errno is set to indeicate the error.
 *            See Execptions for the details.
 * @throw ERANGE input data is too large.
 * @throw ENOMEM unable to allocate memory.
 */
static int QRinput_appendPaddingBit(BitStream *bstream, QRinput *input)
{
    int bits, maxbits, words, maxwords, i, ret;
    BitStream *padding = NULL;
    unsigned char *padbuf;
    int padlen;

    bits = BitStream_size(bstream);
    maxwords = QRspec_getDataLength(input->version, input->level);
    maxbits = maxwords * 8;

    if(maxbits < bits) {
        errno = ERANGE;
        return -1;
    }
    if(maxbits == bits) {
        return 0;
    }

    if(maxbits - bits <= 4) {
        ret = BitStream_appendNum(bstream, maxbits - bits, 0);
        goto DONE;
    }

    words = (bits + 4 + 7) / 8;

    padding = BitStream_new();
    if(padding == NULL) return -1;
    ret = BitStream_appendNum(padding, words * 8 - bits, 0);
    if(ret < 0) goto DONE;

    padlen = maxwords - words;
    if(padlen > 0) {
        padbuf = (unsigned char *)malloc(padlen);
        if(padbuf == NULL) {
            ret = -1;
            goto DONE;
        }
        for(i=0; i<padlen; i++) {
            padbuf[i] = (i&1)?0x11:0xec;
        }
        ret = BitStream_appendBytes(padding, padlen, padbuf);
        free(padbuf);
        if(ret < 0) {
            goto DONE;
        }
    }

    ret = BitStream_append(bstream, padding);

DONE:
    BitStream_free(padding);
    return ret;
}

/**
 * Append padding bits for the input data - Micro QR Code version.
 * @param bstream Bitstream to be appended.
 * @param input input data.
 * @retval 0 success
 * @retval -1 an error occurred and errno is set to indeicate the error.
 *            See Execptions for the details.
 * @throw ERANGE input data is too large.
 * @throw ENOMEM unable to allocate memory.
 */
static int QRinput_appendPaddingBitMQR(BitStream *bstream, QRinput *input)
{
    int bits, maxbits, words, maxwords, i, ret, termbits;
    BitStream *padding = NULL;
    unsigned char *padbuf;
    int padlen;

    bits = BitStream_size(bstream);
    maxbits = MQRspec_getDataLengthBit(input->version, input->level);
    maxwords = maxbits / 8;

    if(maxbits < bits) {
        errno = ERANGE;
        return -1;
    }
    if(maxbits == bits) {
        return 0;
    }

    termbits = input->version * 2 + 1;

    if(maxbits - bits <= termbits) {
        ret = BitStream_appendNum(bstream, maxbits - bits, 0);
        goto DONE;
    }

    bits += termbits;

    words = (bits + 7) / 8;
    if(maxbits - words * 8 > 0) {
        termbits += words * 8 - bits;
        if(words == maxwords) termbits += maxbits - words * 8;
    } else {
        termbits += words * 8 - bits;
    }
    padding = BitStream_new();
    if(padding == NULL) return -1;
    ret = BitStream_appendNum(padding, termbits, 0);
    if(ret < 0) goto DONE;

    padlen = maxwords - words;
    if(padlen > 0) {
        padbuf = (unsigned char *)malloc(padlen);
        if(padbuf == NULL) {
            ret = -1;
            goto DONE;
        }
        for(i=0; i<padlen; i++) {
            padbuf[i] = (i&1)?0x11:0xec;
        }
        ret = BitStream_appendBytes(padding, padlen, padbuf);
        free(padbuf);
        if(ret < 0) {
            goto DONE;
        }
        termbits = maxbits - maxwords * 8;
        if(termbits > 0) {
            ret = BitStream_appendNum(padding, termbits, 0);
            if(ret < 0) goto DONE;
        }
    }

    ret = BitStream_append(bstream, padding);

DONE:
    BitStream_free(padding);
    return ret;
}

static int QRinput_insertFNC1Header(QRinput *input)
{
    QRinput_List *entry = NULL;

    if(input->fnc1 == 1) {
        entry = QRinput_List_newEntry(QR_MODE_FNC1FIRST, 0, NULL);
    } else if(input->fnc1 == 2) {
        entry = QRinput_List_newEntry(QR_MODE_FNC1SECOND, 1, &(input->appid));
    }
    if(entry == NULL) {
        return -1;
    }

    if(input->head->mode != QR_MODE_STRUCTURE || input->head->mode != QR_MODE_ECI) {
        entry->next = input->head;
        input->head = entry;
    } else {
        entry->next = input->head->next;
        input->head->next = entry;
    }

    return 0;
}

/**
 * Merge all bit streams in the input data.
 * @param input input data.
 * @return merged bit stream
 */

static BitStream *QRinput_mergeBitStream(QRinput *input)
{
    BitStream *bstream;
    QRinput_List *list;
    int ret;

    if(input->mqr) {
        if(QRinput_createBitStream(input) < 0) {
            return NULL;
        }
    } else {
        if(input->fnc1) {
            if(QRinput_insertFNC1Header(input) < 0) {
                return NULL;
            }
        }
        if(QRinput_convertData(input) < 0) {
            return NULL;
        }
    }

    bstream = BitStream_new();
    if(bstream == NULL) return NULL;

    list = input->head;
    while(list != NULL) {
        ret = BitStream_append(bstream, list->bstream);
        if(ret < 0) {
            BitStream_free(bstream);
            return NULL;
        }
        list = list->next;
    }

    return bstream;
}

/**
 * Merge all bit streams in the input data and append padding bits
 * @param input input data.
 * @return padded merged bit stream
 */

static BitStream *QRinput_getBitStream(QRinput *input)
{
    BitStream *bstream;
    int ret;

    bstream = QRinput_mergeBitStream(input);
    if(bstream == NULL) {
        return NULL;
    }
    if(input->mqr) {
        ret = QRinput_appendPaddingBitMQR(bstream, input);
    } else {
        ret = QRinput_appendPaddingBit(bstream, input);
    }
    if(ret < 0) {
        BitStream_free(bstream);
        return NULL;
    }

    return bstream;
}

/**
 * Pack all bit streams padding bits into a byte array.
 * @param input input data.
 * @return padded merged byte stream
 */

unsigned char *QRinput_getByteStream(QRinput *input)
{
    BitStream *bstream;
    unsigned char *array;

    bstream = QRinput_getBitStream(input);
    if(bstream == NULL) {
        return NULL;
    }
    array = BitStream_toByte(bstream);
    BitStream_free(bstream);

    return array;
}

/******************************************************************************
 * Structured input data
 *****************************************************************************/

static QRinput_InputList *QRinput_InputList_newEntry(QRinput *input)
{
    QRinput_InputList *entry;

    entry = (QRinput_InputList *)malloc(sizeof(QRinput_InputList));
    if(entry == NULL) return NULL;

    entry->input = input;
    entry->next = NULL;

    return entry;
}

static void QRinput_InputList_freeEntry(QRinput_InputList *entry)
{
    if(entry != NULL) {
        QRinput_free(entry->input);
        free(entry);
    }
}

QRinput_Struct *QRinput_Struct_new(void)
{
    QRinput_Struct *s;

    s = (QRinput_Struct *)malloc(sizeof(QRinput_Struct));
    if(s == NULL) return NULL;

    s->size = 0;
    s->parity = -1;
    s->head = NULL;
    s->tail = NULL;

    return s;
}

void QRinput_Struct_setParity(QRinput_Struct *s, unsigned char parity)
{
    s->parity = (int)parity;
}

int QRinput_Struct_appendInput(QRinput_Struct *s, QRinput *input)
{
    QRinput_InputList *e;

    if(input->mqr) {
        errno = EINVAL;
        return -1;
    }

    e = QRinput_InputList_newEntry(input);
    if(e == NULL) return -1;

    s->size++;
    if(s->tail == NULL) {
        s->head = e;
        s->tail = e;
    } else {
        s->tail->next = e;
        s->tail = e;
    }

    return s->size;
}

void QRinput_Struct_free(QRinput_Struct *s)
{
    QRinput_InputList *list, *next;

    if(s != NULL) {
        list = s->head;
        while(list != NULL) {
            next = list->next;
            QRinput_InputList_freeEntry(list);
            list = next;
        }
        free(s);
    }
}

static unsigned char QRinput_Struct_calcParity(QRinput_Struct *s)
{
    QRinput_InputList *list;
    unsigned char parity = 0;

    list = s->head;
    while(list != NULL) {
        parity ^= QRinput_calcParity(list->input);
        list = list->next;
    }

    QRinput_Struct_setParity(s, parity);

    return parity;
}

static int QRinput_List_shrinkEntry(QRinput_List *entry, int bytes)
{
    unsigned char *data;

    data = (unsigned char *)malloc(bytes);
    if(data == NULL) return -1;

    memcpy(data, entry->data, bytes);
    free(entry->data);
    entry->data = data;
    entry->size = bytes;

    return 0;
}

static int QRinput_splitEntry(QRinput_List *entry, int bytes)
{
    QRinput_List *e;
    int ret;

    e = QRinput_List_newEntry(entry->mode, entry->size - bytes, entry->data + bytes);
    if(e == NULL) {
        return -1;
    }

    ret = QRinput_List_shrinkEntry(entry, bytes);
    if(ret < 0) {
        QRinput_List_freeEntry(e);
        return -1;
    }

    e->next = entry->next;
    entry->next = e;

    return 0;
}

QRinput_Struct *QRinput_splitQRinputToStruct(QRinput *input)
{
    QRinput *p;
    QRinput_Struct *s;
    int bits, maxbits, nextbits, bytes, ret;
    QRinput_List *list, *next, *prev;

    if(input->mqr) {
        errno = EINVAL;
        return NULL;
    }

    s = QRinput_Struct_new();
    if(s == NULL) return NULL;

    input = QRinput_dup(input);
    if(input == NULL) {
        QRinput_Struct_free(s);
        return NULL;
    }

    QRinput_Struct_setParity(s, QRinput_calcParity(input));
    maxbits = QRspec_getDataLength(input->version, input->level) * 8 - STRUCTURE_HEADER_SIZE;

    if(maxbits <= 0) {
        QRinput_Struct_free(s);
        QRinput_free(input);
        return NULL;
    }

    bits = 0;
    list = input->head;
    prev = NULL;
    while(list != NULL) {
        nextbits = QRinput_estimateBitStreamSizeOfEntry(list, input->version, input->mqr);
        if(bits + nextbits <= maxbits) {
            ret = QRinput_encodeBitStream(list, input->version, input->mqr);
            if(ret < 0) goto ABORT;
            bits += ret;
            prev = list;
            list = list->next;
        } else {
            bytes = QRinput_lengthOfCode(list->mode, input->version, maxbits - bits);
            if(bytes > 0) {
                /* Splits this entry into 2 entries. */
                ret = QRinput_splitEntry(list, bytes);
                if(ret < 0) goto ABORT;
                /* First half is the tail of the current input. */
                next = list->next;
                list->next = NULL;
                /* Second half is the head of the next input, p.*/
                p = QRinput_new2(input->version, input->level);
                if(p == NULL) goto ABORT;
                p->head = next;
                /* Renew QRinput.tail. */
                p->tail = input->tail;
                input->tail = list;
                /* Point to the next entry. */
                prev = list;
                list = next;
            } else {
                /* Current entry will go to the next input. */
                prev->next = NULL;
                p = QRinput_new2(input->version, input->level);
                if(p == NULL) goto ABORT;
                p->head = list;
                p->tail = input->tail;
                input->tail = prev;
            }
            ret = QRinput_Struct_appendInput(s, input);
            if(ret < 0) goto ABORT;
            input = p;
            bits = 0;
        }
    }
    QRinput_Struct_appendInput(s, input);
    if(s->size > MAX_STRUCTURED_SYMBOLS) {
        QRinput_Struct_free(s);
        errno = ERANGE;
        return NULL;
    }
    ret = QRinput_Struct_insertStructuredAppendHeaders(s);
    if(ret < 0) {
        QRinput_Struct_free(s);
        return NULL;
    }

    return s;

ABORT:
    QRinput_free(input);
    QRinput_Struct_free(s);
    return NULL;
}

int QRinput_Struct_insertStructuredAppendHeaders(QRinput_Struct *s)
{
    int num, i;
    QRinput_InputList *list;

    if(s->parity < 0) {
        QRinput_Struct_calcParity(s);
    }
    num = 0;
    list = s->head;
    while(list != NULL) {
        num++;
        list = list->next;
    }
    i = 1;
    list = s->head;
    while(list != NULL) {
        if(QRinput_insertStructuredAppendHeader(list->input, num, i, s->parity))
            return -1;
        i++;
        list = list->next;
    }

    return 0;
}

/******************************************************************************
 * Extended encoding mode (FNC1 and ECI)
 *****************************************************************************/

int QRinput_setFNC1First(QRinput *input)
{
    if(input->mqr) {
        errno = EINVAL;
        return -1;
    }
    input->fnc1 = 1;

    return 0;
}

int QRinput_setFNC1Second(QRinput *input, unsigned char appid)
{
    if(input->mqr) {
        errno = EINVAL;
        return -1;
    }
    input->fnc1 = 2;
    input->appid = appid;

    return 0;
}
